Bevel-gear-grinding machine.



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BEV'EL GEAR GRINDING MACHINE.

APPLICATION FiLED MAY 9| '|913- Patented J an. 11, 1916.`

5 SHEETS-SHEET l.

F. A. WARD.

BEVEL GEAR GRINDING MACHINE. APPLICATION FILED MAY 9, |913.

Patented Jan. 11, 1916.

F. A. WARD. BEVEL GEAR GRINDING MACHINE.

APPLICATION FILED MAY 9, 1913.

1,167,957., A Patented 131,11, 1916.

5 SHEETS-SHEET 3.

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` F. A'. WARD. sEvEL GEAR GmNmNG MACHINE.

l I APPLICATION FILED MAY 9, |913. 1,167,957. Y' Patented Jan. 11, 1916.

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^ F. A. WARD. BEvEL GEAR Gmunms MACHINE. A APPLICATION f lLED MAY 9| 1913.. 1,167,957, Patented Jan. 11,` 1916.

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FREDERICK ALEXANDER WARD, OF DETROIT, MICHIGAN, ASSIGNOR TO GEAR GRIND- ING MACHINE COMPANY, OF DETROIT, MICHIGAN, A CORPCRATION 0F MICHIGAN.

BEVEL-GEAB-GRINDING MACHINE.

Specification of Letters Patent. patntd Jan., 11, 1916.

Application led May 9, 1913. Serial No. 766,544.

To all whom it may concern:

Be it known that I, FREDERICK A. WARD, a citizen of the United States of America, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Bevel- Gear-G-rinding Machines, of which the following vis a specification, reference being had therein to the accompanying drawings.

This invention relates to grinding machines, and more particularly to a machine of the type mentioned which is adapted for grinding toothed bevel wheels.

In the drawings: Figures l, 2 and 3 are diagrams illustrating three different positions in the operation of grinding a bevel wheel tooth in accordance with this invention. Fig. 4 is al side elevation of one side of a bevel wheel grinding machine constructed in accordance with this invention and Fig. 5 is a similar view of the other side ofthe machine. Fig. 6 is a plan of the machine, and Figs. 7 and'S are end elevations respectively showing opposite ends of the machine. Fig. 9 is a yfront elevation of the wheel trimming device.

The same reference letters in the different views indicate the same parts.

The principle underlyingthe construction of the machine hereinafter described will be first described with reference to Figs. l to 3. In such figures the section of one tooth c of a bevel wheel is there shown. The wheel rotates about the aXis b, and the oppositefaces of each tooth converge toward a point which lies on the aXis b in the ordinary manner. tates about its aXis d andalso reciprocates along the face of the tooth under treatment in a direction to and from the converging point of the tooth faces. At the same time as the bevel wheel rotatesthe grinding wheel travels laterally in a horizontal direction, and during such movement it is constantly reciprocating as above described. In the initial position the grinding wheel and tooth are in the relationship shown in Fig. l. While the tooth moves in the direction of the arrow successive portions of' the tooth face are subjected to the. actionv of the grinding wheel until the position-indicated by Fig. 2 is reached. During the continued movement of the tooth theilatter The grinding wheel e ro` gradually leaves the grinding wheel until the position indicated by Fig. 3 is reached. Herethe grinding wheel is moved laterally to bring its. opposite grinding face into the operative position. Also the horizontal motion of the grinding wheel is reversed. But before the rotation of the bevel wheel is reversed the said wheel remains stationary until the grinding wheel has moved into contact with the face of the next tooth adjacent to that operated on in the first described motion. Both bevel wheel and grinding wheel then perform the return motion together. When the bevel wheel reaches its initial position, the grinding wheel receives a lateral motion in the opposite direction to that above mentioned and is thus brought back to the position shown in Fig. l: the bevel wheel also is advanced through an angular distance equal to the lpitch of the teeth. The above .described sequence of operations is then repeated.

' It has been proposed in bevel wheel grinding machines to reciprocate a `revolving grinding wheel across the teeth of bevel wheels which receive both a rolling and an oscillatory motion, or to roll only the toothed wheel and impartboth a radial and a reciprocating motion to a rotating grinding wheel. In machines constructed in accordance with this invention, the wheel is rolled, and in addition to a reciprocatory motion al lateral oscillatory motion is imparted to the rotating grinding wheel; by such motions we are able to approximate most closely tothe motion of two toothed wheels rolling together and obtain the best form of tooth.

In the construction of a bevel wheel grind- ',ries the grinding wheel or disk c. The latter is rotated by a belt' passing over the pulley 7c or by motor. For periodically trimming the grinding -wheel a suitable trimmerv is mounted 1n conjunction wlth the -slide z'- adjacent to the wheel. Such trimmer comprises in the arrangement shown three .diamond or like tools Z mounted on -a transverse slidem. Such slide is carried by a rotatable piece n which is mounted upon a -slide 0, and the latter is supported by a of the grinding wheel. To trim one of the inclined faces of the wheel the piece n is x rotated to bring the slide m into a suitable A belt or other suitable means rotation is obinclined position when one of the outer tools can be moved across the said face of the Wheelrfor,l trimming the same. A similar angular movement in the opposite direction brings the :other tool into position for act ing 0n the other inclined face of the wheel.

A 'peg Q entering suitable apertures in the partj n serves to locate the slide min the required positions. The contour of the grinding wheel' may differ for different classes of work, but ordinarily it consists of a pair of fiat grinding'surfaces disposed at a suitable angle to the periphery of the wheel as shoav'n. The part r which carries the grinding wheel is mountedin such a manner with respect to theslide z' that it may be moved laterally. in either direction to permit the wheel to be adjusted sidewise for operat ing on either of the faces of the Wheel tooth. Further details of the means for producing tliis motion are given hereafter.

Four principal motions are required in the machine in addition to rotation of the grinding disk, namely, (a) rotation of the work during the grinding operation on each tooth,l lateral movement through an arc of a 'circle of the vsaddle of the grinding wheel slide simultaneous with the first mentioned motion, (c) rec-.iprocation of. the slide and (d) periodic rotational advance of the work (or indeXing) to present a new tooth to the action of thewheel. The means for producing such .motions are now described in the above mentioned order.

From a first motion shaft s driven by a tained of a secondshaft t through worm reducing gear u and fromv a cam o mounted .on the second shaftintermittent yoscillation is produced in a' lever w which reciprocates horizontal bar having a pair *ofA racks and ,1/ formed thereon. The cam is proportionedto provide a suficient pause after each' complete oscillation or double movement) of the lever to permit the'indeXing or advance ofthe work to take place. From the rack y motion is transmitted through wheels e, 2 and 3 to a pinion 4 engaging a circular rack 5 on the saddle h, and from the other rack ai motion is likewise transmitted through wheels 6, 7, 8 and 9' to a wheel 10 connected to a spindle 11 carrying the work. ln the drawings only a portion of the spindle 11 is shown, and the work piece thereon is omitted for clear-ness of illustration of the machine. It will be undei-stood that the said spindle projects toward the centralpoint of the machine and carries at its outer end the wheel to be ground. .F rom the foregoing it will be seen that simultaneously with the partial rota* tion or rolling of the work to present the' whole of one face of a tooth to the action of the grinding wheel the 'required motion in a horizontal plane through a suitable arc of a circle is -imparted to the saddle of the grinding wheel slide. Concurrently with such motions the grinding wheel is reciprocated rapidly by its slide across the face o the wheel tooth.

Reciprocation of the grinding wheel slide is effected by an adjustable crank and convnecting rod or their equivalent which are driven independentlyby a belt or other convenient means. The mechanism shown in the drawings comprises a belt pulley 12 and gear wheel 13 and 14 carried on a bracket 15 on the saddle hi. @ne eind of a connecting rod 16 is adjustably attached to a radial slot in the wheel 14, and the other end of the said rod is connected to a crank 17 secured to a disk 18 which is attached to.

i a gear wheel 19 engaging a rack 20` at the underside of the slide i. The disk 18 and wheel 19 are angularly adjustable relatively to each other. The radial adjustment of the connecting rod at the Wheel 14 permits the stroke ofthe slide to be varied, and the angular adjustment of the disk 18.permits the position of the slide to be varied.

Periodic advance or indexing of the work through the required angular distance after each complete operation of the grinding wheel on the side of a tooth is produced as follows The work carrying spindle '11 i's mounted on a headstock 21 on the semicircular slide 1 above mentioned, andI in conjunction with such spindle is arranged a pair of concentric sleeves 22 and 23. rllhe outer sleeve 22 carries the gear wheel 10 which imparts the rolling motion to the work, While on the inner sleeve 23 ismounted a worm whee124 engaging with a worm 25 which is carried on a case 26 or bracket 'mounted loosely on the said sleeve 23. rllhe vlatter sleeve also has secured to it ythe work or the other of a pair of like abutments 28 on \125 the wheel 10 and vsufficient space is provided between the abutments to permit the said wheel to move through a certain distance independently of the case. By lock- 1ng the' worm wheel 24 and case 26 orv bracket together the rolling motion can be imparted to the spindle from the gear Wheel and during such motion the Worm is swung out of engagement With a shaft 67 Which in one position it engages for receiving the indexing the Worm Wheel from the case or bracket When the Worm is in engagement With its driving shaft the indexing motion can be imparted to the spindle. To produce the indexing motion, movement is transmitted from the first motion shaft s through suitable bevel gearing 29, 30 and 31, intermediate shafts and Worm gearing 32 to a crank 33 Which oscillates through a rod 34 a gear Wheel 35 actuating a reciprocatory rack 36, such transmission mechanism being constructed or arranged in any convenient manner asshown to permit the required adjustments of the Work saddleg on its guide f to suit the angle of the tooth under treatment. The rack 36 rotates a Wheel 37 gearing With a Wheel 38 and from such Wheel 38 motion in one directiononly is taken through a one-Way clutch (e. g. a ratchet. and pawl device 39) through suitable intermediate Wheels 40 and 41 and change gear (indicated collectively by 42) to the driving shaft 67 of the Worm 25. Connection of the shaft and Worm is effected by a projection on the end of one part Which enters a slot in the adjacent end of the other. Such a connection provides in a convenient manner for the required Withdrawal of the Worm from its driving shaft'or spindle during the rolling motion of -the Work. In conjunction with the mechanism just described is arranged acam actuated and spring controlled locking catch which prevents accidental motion of the indexing mechanism during the interval of rest. The catch 43 engages a disk 44 secured to kone of the Wheels in the train 42 and is attached to one end of a spindle 45. Alongside the catch is a freely pivoted'spring controlled lifting piece 46 which can move to a small extent independently of the catch 43.; Such lifting piece is arranged in coperation With a cam 47 Which is rotated firstin one direction and then in the other by a7 gear Wheel 48 driven from the Wheel 37 through the Wheel 38. The cam has a circulargroove in one face which can engage a lateral projection on the lifting piece, and between such groove and the periphery of the cam is a notch which permits the said projection to pass to the outer periphery of the cam. Further, the edges of the notch are oppositely inclined, so Ythat in one direction of rota.`

tion of the cam the liftingy piece -is raised and its projection caused to ride on the periphery of the cam, thus raising and hold@ ing the catch out of actiorri While in the opposite direction of rotation the lifting piece is depressed so that its projection occumotion. By unlocking pies the groove in the cam and the catch is held in the operative position. In conjunction With the case 26 and the Worm Wheel 24 is arranged a lock which secures the Said parts together. Such lock comprises a plunger 49 on the case which presses against the Worm Wheel and holds the parts by frictional contact. 'When the catch 43 is' lifted for releasing the indexing mechanism a lever 50 on the catch spindle 45 presses a spring actuated plunger 51 which by acting on a lever 52 attached to the locking plunger 49 liberates the Worm Wheel. The required indexing motion can then be imparted to the Work by the mechanism above described, While the mechanism producing the rolling motion aforesaid remainsstationary. When the indexing has been effected the lock is restored to its original position. The Worm Wheel 24'and case 26 are then secured together and motion can be transmitted through the same from the Wheel 10 to the Work spindle 11 for effecting the rolling motion of the Work.

lt Will be understood that suitable provisions are made Where required for appropriate adjustments of the positions of the various parts of the machine and the transmitting gears, so that the machine can be set to operate on Wheels of any pitch, diameter and angle and other dimensions Within the limits for which the machine is designed. To permit the Work to be Withdrawn out of range of the grinding Wheel for convenience in ixing a neuT piece in position the bracket 21 carrying the Workis arranged to slide on the saddle g.

On reference to Fig. 3 it will be seen that in addition to the'lateral movement required to bring the opposite face of the grinding Wheel into position for acting on a face of a tooth during the return movement of the bevel Wheel and grinding Wheel to the original or Fig. 1 position, a. lateral movement of the grinding Wheel independently of the bevel Wheel is required to bring the grinding wheel into contact with the tooth.

This is effected by the lost motion between the abutments 27 and 28 Von the Wheel 10 and case 26. During the initial part ofthe return rotationof the Wheel 10 no rolling motion is imparted to the Work. But as soon as the grinding Wheel reaches the proper position both the grinding Wheel and the bevel Wheel move together. To produce the required lateral movement of the grind-4 lbracket '7'. The levers 55 are connectedby lao levers 54 to a horizontal sliding piece 56 which by means of a peg 57-engages an inclined slot in a vertical sliding piece 58. The latter has a rack formed at its lower end and with such rack engages a pinion 59 on the spindle of a lever 60. Between .the said lever 60 and another similar lever 61 carried on the slide z' is arranged a connecting rod 62 provided with adjustable stops 63. On the saddle carrying the slide z' are located a pair of laterally movable stops 64 actuated by a bar 65, each of such stops being formed with an inclined slot which is engaged by a peg on the bar. Further the bar is attached to a bell crank lever 66, which at one end is adapted to press under the action of a spring against the segmental edge of theguide which carries the saddle h as shown in the plan at Fig. l6, and also to enter slots in the said edge near each limit of the movement of the saddle. When the saddle approaches one end of its movement the bell crank lever enters the adjacent slot and is there arrested. Continued mo tion of the saddle causes the lever to rotate suiiciently to impart the required longitudinal motion to the bar 65 for advancing one of the stops 64. During the next reciprocation of the slide on of the stops 63 strikes the advanced stop 64k and the rod 62 is thereupon held, sotha't!l as the slide completes its motion the levers 60 and 6l are swung on their pivots and the required lateral inotion is imparted to the bracket 7' carrying the grinding wheel through the pinion 59,

Y sliding pieces 58 and 56 and levers 54 and 55. A similar operationoccurs when the saddle reaches the other limit of its motion,

'excepting that the other stops are .brought I the character of the work under treatment.

To compensate for wear and to accommodate wheels of different diameters, the bracket 7' is vertically adjustable on the slide Y A machine as above described is more especially suitable for finishing to the required dimensions bevel gears or the like which .have been previously roughly machined and hardened.

ln a modification, instead of a grinding wheel any suitable reciprocating orI otherwise moving abrasive means may be einployed with appropriatemechanisms for actuating thev same.

abrasive element, means for periodically re-y AWhat I claim as my invention is: l. In machines for grinding toothed bevel wheels and the like, the combination of an storing the contour of the saidelement, a

reciprocatory slide upon which -the abrasive element is mounted, a saddle carrying the rolling and indexing motions are intermittently imparted to the work. l

2. ln'machines for grinding toothed bevel wheels or the like, the combination 'of a reciprocatory slide, a grinding Wheel and trimming means for said wheel mounted on the slide, a saddle carrying the slide and movable laterally in a circular path, a Work support, and means for producing simultaneous movement of the saddle in a circular path and rolling motion of the work.

3. ln machines for grinding toothed bevel wheels and the like, the combination of a grinding wheel formed with a pair of inclined grinding faces or edges, a reciproca tory slide carrying the wheel, a saddle carrying the slide and movable laterally in a circular path, a wheel carrying bracket mounted on the slide and movable laterally thereon, and means arranged in part on the slide and in part on the saddle for imparting a lateral movement to the bracket at the completion of each grinding operation on a tooth face.

4l. In machines .for grinding toothed bevel wheels and the like, the combination with a saddle movable laterally in a circular path. and carrying a reciprocatory slide on which a grinding Wheel is mounted, and a Work support, of means for producing simultaneous movementl of the saddle in its circular path and rolling motion of the Work.

5. ln machines for grinding toothed bevel wheels and the like, the combination with means comprising a rack or a pair of racks for producing simultaneous motion, of a saddle carrying a reciprocatory slide and grinding wheel, and a rotatable work support, of a lever and an operating cam adapted to provide an interval of rest after each double stroke of the rack or racks.

6. ln machines for grinding toothed bevel wheels and the like, the combination of a work supporting spindle, a pair 'of concentric sleeve, a worm wheel connected to one ofythe sleeves, and avspur wheel connected tothe other sleeve, a case or bracket arranged in conjunction with the Worm wheel and carrying a worm, a lock for securing the worm wheel to the said case or bracket, driving abutments between the spur wheel and case orbracket, means for rotating the spur wheel and imparting a rolling motion 7. In machines for grinding toothed bevel wheels and the like, the combination with 4a Worin and .worm Wheel actuating a work carrying spindle, of a reciprocatoryrack, a

wheel'train and a one-Way clutch for rotatla@ ing the spindle through the worm mechanism when the rack is moved in one direction, and a cam controlled catch for preventing motion of the Work mechanism during the opposite motion of the rack.

8. The combination With an organized machine for grinding gear Wheels and the like including a rotary Work holder, an indexing mechanism therefor and a grinder having its axis transverse to thel axis of the Work, of means forming a part of the organized unit for periodically trimming the grinder ywheel to produce and maintain a predetermined surface contour, and means for. relatively moving said grinder wheel and Work holder to develop by said trimmed surface a series of like segments in the contour of the iinished Work non-complemental to said trimmed surface.

9. In a machine for grinding toothed bevel Wheels and the like, the combination with a grinding Wheel, of a relatively-movable Work support, mechanism for imparting rolling motion to the Work, and means for eiecting the non-rotation of the Work at the end of each grinding operation to permit the grinding wheel to advance into contact With the face of the tooth to be ground.

10. In a machine for grinding toothed bevel Wheels and the like, the combination With a grinding Wheel, of a Work support for the. Work, means for simultaneously moving said grinding Wheel laterally and rotating the Work, and means for effecting the non-rotation of the Work after each grindlng operation to permit the grinding Wheel to reach the proper positionrelative to the Work upon its return movement.

11. In machines for grinding toothed bevel Wheels and the like, the combination of a `'Wheels and the like, the combination with a grinding Wheel, of a Work support, means for producing simultaneous lateral movement of said grinding Wheel and rotation of the Work carried upon said Work support, and means for producing a longitudinal reciprocation of said grinding Wheel.

13. In a machine for grinding toothed bevel Wheels and the like, the combination with a saddle and a gear Wheel uponsald saddle provided With a radial slot, of a reciprocatory slide carried by said saddle, a rack on said slide, a gear Wheel engaging said rack, a disk angularly adjustably attached to said gear Wheel, and a connection engaging said disk and the radial slot of said gear Wheel. upon the saddle.;

In testimony whereof I aiiiX my signature in presence of two Witnesses.

FREDERICK ALEXANDER WARD. Witnesses: f

vERNEST HARKER,

NOBLE'C. BANKS.

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